Jalal M. Jalil

University of Technology, Iraq · Department of Electro-Mechanical Engineering

The effect of using phase change material (PCM) on the performance of the heat sink cooling was investigated in this study. Experiments of the heat sink cooling subjected to several input powers (11 W, 13 W and 15 W) to and air flow velocities (3.4 m/s, 2.5 m/s, and 1.5 m/s) have been conducted with two different case studies with and without PCM....

The focus of this paper is on a thermal performance of the window solar air collector with seven-moveable circular perforated absorbent plates that controlled manually. The proposed window solar air collector is a solar thermal system which can be employed to preheat the ventilation air supply and compromise between sunlight penetration to the desi...

In this paper, the thermal analysis of the Iraqi building wall consists of mortar layers and brick containing phase change material (PCM) for use in hot climates is provided. The aim of using the PCM is to use its high latent fusion heat to reduce the temperature by absorbing heat from the bricks during the fusion process before it reaches the inte...

In this paper a new model has demonstrated that it operates in a moderate performance scale to generate hot water. In its early stage, the preliminary model, which built with double pass water tube inside evacuated tube, was investigated experimentally. The model was tested inside room under different operation conditions in terms of solar radiatio...

The aim of this study is to analyze the phase change material cooling performance integrated into heat sink experimentally. A paraffin wax as phase change material is used in this experiment and it placed under the heat sink with thickness 30 mm, various power input at 11 W, 13 W and 15 W used in this experiment to generate heat at different levels...

New arrangements of the wavy fins structure were implemented on the absorber.  The wavy fins obstruct the flow on both passes of the double passes collector.  Thermal efficiency reached 84% with the new arrangements. In this paper, experimental study on double pass solar air heater with wavy fins absorber has been investigated. The fins attached...

Window solar air collector is a significant instrument for heating residential buildings in cold regions. This paper presents an experimental investigation of the thermal performance of a window solar air collector with seven moveable absorber plates, as each plate contains 28 circular perforations. The 7 plates opened and closed at different angle...

In this paper, a new design, fabricate and investigate the performance of the parabolic trough systems (PTC) by using double pass water passage in evacuated tube technology. This system can be used for heating water in winter season without assistive devices. The double-pass method utilizing to improve thermal performance for PTC by increasing the...

Natural laminar convective fluid flow has been simulated inside inclined rectangular cavities with and without internal heat generation for different aspect ratios and inclination angles. The most important basic dimensionless parameters for this problem are the external Rayleigh number (RaE) and the internal Rayleigh number (RaI), where RaE refers...

In this paper, an experimental investigation of the integration of PCM capsules as insulation material into the outer or inner rows of hollow brick to find out the optimum location of the PCM capsules that give the best thermal performance of a wall. A test model consists of two identical cubical rooms was designed and fabricated to test the wall w...

In this study, an experimental and numerical work aims to analyze and investigate PCM capsules' use as an insulation material into the hollow bricks that form a wall. A novel model of plug and play wall system consisting of two identical rooms was designed and fabricated to test two southern walls with and without PCM in the outdoor natural conditi...

In this paper, numerical study on double pass solar air heater with wavy fins absorber has been investigated. The fins attached to the upper and lower surfaces of the absorber. Three wavy fins arrangement (3, 5 and 7 fins) have been investigated with plan absorber by changing solar radiation intensity (500, 600, 700 and 800 W/m2), air mass flow rat...

Numerical modeling based on finite-volume method (FVM) SIMPLE algorithm was established to analyze the 3D-turbulent flow in the wavy two-pass solar collector is proposed. This model is used to analyze and simulate the performance of a V-grooved absorbent collector. The main parameters of an air velocity ranging of(1,1.5 and 2 ) m/sec, and solar rad...

This paper describes the case of combined free and forced convection heat transfer to a thermally developing air flow in a horizontal rectangular duct which has been studied experimentally for laminar internal flow. The heated surfaces were subjected to a constant heat flux while the duct short sides were kept unheated, for three cases lower, upper...

In this paper, the performance of double glazed window filled with paraffin wax is analyzed numerically and experimentally to evaluate the improvement in the thermal performance and comfort of a room located in Baghdad, Iraq using paraffin wax. The proposed approach aims to reduce the required cooling load in the summer season and temperature fluct...

In this paper, an experimental study has been conducted for using a PCM as a thermal insulation material in a south wall of a room. Two identical cubic rooms were fabricated from sandwich panels except for the south wall (test wall) was built as an Iraqi domestic wall. South wall orientation was chosen as the test wall due to the significant amount...

This paper studies the control of radiation on double-pass solar air heaters with porous media in the lower channel. The intensity of radiations was controlled in two ways potentiometer and mobile via the Bluetooth by designing, building, and implementing a light control system which consists of a power supply, transformer, two Arduino microcontrol...

This study describes an experimental investigation of the thermal efficiency of stainless steel mesh and steel wool as a porous medium in the lower channel of a double pass solar air heater. An experimental setup was planned and developed. Various types of porous media with high thermal conductivity and with different porosities have been tested. T...

Two numerical models are accomplished to predict thermal effectiveness of a novel solar heater with and without paraffin-based on the latent heat storage. The conservation equations with enthalpy transforming method of phase change material (PCM) are analyzed using finite-volume with an explicit scheme. The influence of the main parameters is inves...

The solar energy system is environmentally friendly and the utilization of photovoltaic thermal collectors, (PV/T) has attracted more attention, which directly converts solar radiation into electricity and thermal energy simultaneously. This study investigated the air biased Photovoltaic thermal hybrid solar collectors, (PV/T) trend for two cases,...

In this paper, a numerical investigation has been performed to study the effect of varying the thermal properties of the paraffin wax on the performance of a double glazed window doped with it during the summer climate of Baghdad (33.3 °N, 44.4 °E). Using FORTRAN (f 90) constructed computer program, finite difference combined with the enthalpy meth...

Over the years, there has been rigorous modification of solar collectors for the thermal needs of the era to be efficiently served. A variety of design innovations have paved their way into the invention of novel ways of securing more solar energy as useful heat. Primarily, this study investigates the effects of multi air inlets on the transfer of...

A numerical three-dimensional investigation is performed to estimate the optimum doping content (i.e. thickness) of the PCM filling a double glazed window. For the summer weather of Baghdad, Iraq. Finite Volume method combined with the enthalpy method is utilized to acknowledge the conduction related with phase change problems within the wax by usi...

The thermal performance of a new solar air collector with corrugated packing is studied in this work. A new innovate shape was suggested in this paper to improve the thermal performance of the solar air collector. Mathematical models are developed to investigate the thermal performance of the collector and the results are verified by experiments. E...

This study experienced the performance of air biased PV/T collector partially covered with glass at various values of irradiance (400, 600, 800, 1000) W/ m ² and constant ambient temperature. A three various configurations have been demonstrated in this work, case A (glass at inlet portion), case B (glass at mid portion) and case C (glass at outlet...

The heating of air flow through micro-channel was studied experimentally and numerically to examine the improvement in the thermal performance achieved by micro-channel. Numerically, laminar incompressible 3D steady-state Navier Stokes equations were solved by Finite volume method. Experimentally, a rig was built to investigate the cooling of air f...

The impact of micro-pin fins on heat transfer performance in this study is analyzed numerically. Navier-Stokes equations are solved by steady-state three dimensions turbulent forced convection. Various numbers of micro-pin fins with in-line configuration and different micro-pin fins configurations such as staggered configuration additionally to the...

Phase Change Materials (PCMs) mainly used for Thermal energy storage. Computational Fluid Dynamics (CFD) is used to investigate numerically the temperature distribution over the time for water flowing inside the pipes of solar collector and the PCM placed on the back layer of the collector as a storage media. Phase change problems were solved using...

The present study deals with the prediction and distribution of temperature of air that is contained in an enclosure (test room). The test room is equipped with a concrete thermo storage wall (Trombe wall). All walls of the room are thermally insulated except the one that is facing the sun light. The latter is composed of an external layer of glass...

A numerical three dimensional investigation is performed to study the effects of the heat flux and Reynolds number on the local heat transfer distribution on smooth flat plate surface impinged with normal air jet. Reynolds number based on nozzle exit condition is varied between 1000 and 4000 and heat flux from 500 to 1000 W/m2. The flow domain was...

A mathematical model to analysis three-dimensional forced convection turbulent flow in a novel solar air heater integrated with multiple rectangular capsules filled by paraffin wax-based on phase change material PCM was implemented. The investigations were performed under three airflow speed of (0.6, 1.2, and 1.8) kg/min and average solar irradianc...

The thermal effective and storage performance of a double-pass solar air heater (DP-SAH) without and with PCM were investigated experimentally and numerically. The main objective of this study is to analyze the practicability of a solar air heater integrating with latent heat storage (LHS) unit for applications of household heating and drying paddy...

Abstract- In this study, the effect of vacuum with micro-channel technique on solar air collector performance is investigated experimentally. Vacuum space reduces the loss of heat for the absorption plate by conduction and thus improves the solar collector performance. It has been demonstrated that the solar collector is evacuated to 0.1 bar of pre...

The use of the micro-channel technique is available in many applications, but its applications in the solar collectors are very few, so this research makes a clear contribution in this field. The heat transfer to the flowing air is improved by using micro-channel technique. Numerical and experimental of the impact of micro-channel technique on sola...

Abstract. Using Computational Fluid Dynamic (CFD), a gas turbine with an air-cooled blade was analyzed thermally. In terms of design, the domain was divided into three regions. The first region is the blade to blade passage (external flow) governed by a quasi- 3-D Euler equation in a conservative form. Mac-Cormack's technique algorithm based on the...

The solar air heater is a device rises air flowing temperature in numerous engineering applications as; heating of buildings, and agricultural crops drying. An indoor investigation was experimentally established using the solar simulator to test the flat plate double-pass solar air heater performance with and without paraffin wax-based on phase cha...

This paper aims to investigate and analyze the thermal performance of a double-pass solar air heater using multiple rectangular capsules filled with paraffin wax-based on a phase change material PCM. An indoor projector simulator was used to test a new system during the charge/discharge process. In order to verify the accuracy of these readings, a...

Thermal storage performance of a double-pass solar air collector DP-SAC integrated with multiple rectangular capsules filled by paraffin wax-based on phase change material PCM was investigated experimentally. An indoor experimental using a solar simulator to investigate the melting/freezing period in the DP-SAC. The investigations were performed at...

Abstract- In this study, the effect of vacuum with micro-channel technique on solar air collector performance is investigated experimentally. Vacuum space reduces the loss of heat for the absorption plate by conduction and thus improves the solar collector performance. It has been demonstrated that the solar collector is evacuated to 0.1 bar of pre...

Abstract. An investigation of the thermal performance of flat plate two-pass solar air heater without and with wax has been experimentally carried out by using the solar simulator. The readings were represented for studying the melting/freezing time to test the system for different air mass flow rate (MFR) of (0.6, 0.9, 1.2, 1.5, and 1.8) kg/min an...

Student outcomes attainment represents the core of the ABET accreditation. In this paper, a details of the four years' work in Energy and Renewable Energy Program in Electromechanical Engineering Department in University of Technology was demonstrated, concentrating on the process of student outcomes attainment measurement. The attainment of studen...

This work aims at utilizing the paraffin wax (PCM) latent heat of fusion and calculates the effect of coupling aluminum fins with PCM, to regulate PV cells temperature for the sake of enhancing performance. Absorbing the heat energy from its surface was investigated experimentally and numerically. From the experimental results and the numerical sim...

Research has been undertaken on heat pipe evacuated tube solar collector (HP-ETSC) for hot water applications, which is common in most Middle East regions. The enhancement in thermal performance by using various types of acetone based nanofluids has been explored. This work includes two experimental parts of the gravity-assisted heat pipe (GAHP) in...

A Combined numerical and experimental problem of outward melting of ice around isothermal horizontal cylinder is studied. In theoretical work, a finite volume is used to discretize transient heat transfer energy equation in cylindrical geometry with cylindrical coordinates. The Line Successive Over Relaxation (LSOR) method is used to solve the desc...

In this study, solar air heater with thermally conducted multi V shaped baffles and with same baffles and ribs are investigated experimentally and numerically to improve the performance of conventional air heaters. Numerically, steady state 3D forced convection turbulent model is used to solve Navier Stokes and energy equations of airflow inside re...

Experimental and numerical study of fluid flow and heat transfer in microchannel airflow is investigated. The study covers changing the cooling of micro-channel for the velocities and heater powers. The dimensions of the microchannel were, length = 0.1m, width = 0.001m, height = 0.0005 m. The experimental and numerical results were compared with th...

This paper investigates numerically and experimentally fluid flow and heat transfer inside the desktop P.C.. The study of cooling considers the components; CPU, heat sink, power supply, motherboard, CD, HDD and fans. Three components have heat source (CPU, motherboard and power supply unit). There were two openings for air inlet and two for air out...

In this study, solar air heater with straight shaped baffles is investigated numerically and experimentally to improve the thermohydraulic performance by changing the height of the duct to find the optimum value. Numerically, steady-state 3D forced convection turbulent model is used to solve Navier Stokes and energy equation of air flow inside rect...

This study investigated numerically and experimentally fluid flow and heat transfer in the desktop PC. Three patterns of the positions of air inlet and outlet were tested to find the best one for cooling. The computer components in the present study are CPU, finned heat sink, power supply, motherboard, CD, HDD and fans. Three components which were...

Experimental investigation of packing absorber was carried in Iraqi environment. 14 and 16/11/2017 in Kut province were chosen to carry the investigation. Four velocities (1, 1.1, 1.2 and 1.3 m/s) were used. Inside lighting was used to simulate the measured solar flux of the mention two days. The performance was investigated through measuring exit...

In this numerical research, the heat transfer modes in solar collector are enhanced to increase its thermal performance by using louvered absorber. Three dimensional steady state turbulent air flow was solved by finite volume while three dimensional steady finite difference was used in glass and absorber walls. These two solutions have worked simul...

In this paper, an experimental study has been carried out on the thermal performance of PCM by using it in solar collector. The research was performed in lab condition with different heat flux. The solar collector consists of a unique system. The system consists of evacuated tube ET, thermosyphon TH, water tank with container of phase change materi...

The aim of this study is numerical model of a solar collector, type, evacuated glass tube combined with thermosyphon and using paraffin wax as phase change material SCETHPCM to benefit from the energy stored in this material. Through the use of solar simulator system a different heat is obtained as two values 750 W/m 2 , 1000 W/m 2 have been used,...

In the present work, the investigation on the performance of series of solar air collectors to obtain high temperature air was performed. The first collector has been studied experimentally, while the rest of the series collectors have been investigated numerically with the same boundary conditions. The experimental and numerical results of the fir...

An experimental and numerical investigations are conducted on a Two Phase Closed Thermosyphon (TPCT) charged with six working fluids; namely (water, methanol, ethanol, acetone, butanol and R134a) with filling ratios (40, 50, 60, 70 and 100 %). The TPCT is made from a 0.016 m diameter copper tube, which consists of a 0.15 m evaporator, 0.1 m adiabat...

Research has been undertaken on thermosyphon heat exchangers (THEs) for coolness recovery in sub-tropical climates conditions to explore the potential for energy savings and humidity control in HVAC systems through using THEs. This work includes an experimental and numerical model of THEs install in HVAC system. The performance of these individual...

This paper presents a study of improving the performance of solar collector heat pipe by increasing condenser length. The experimental rig consists of a heat pipe inserted in a water tank for heating. The dimensions of copper thermosyphon (heat pipe) are: inner diameter 14 mm, outer diameter 16 mm, fixed evaporator length 1.15 m and variable conden...

The present study is focused on the effect of oxygen enrichment (as oxidizer) on the flame characteristics of premixed flame of Iraqi Liquefied Petroleum Gas (LPG),which consider the first measurements of laminar premixed flame speed for (LPG) with oxygen enrichment. A test rig is designed and fabricated to measure the laminar flame speed using a t...

Finite volume method was used to investigate the thermal performance and phase change of wax paraffin layers surrounding heated water tank (1 m cube). Different timing of heater power on (on and off hours) and different thickness (0.06, 0.1, 0.133 and 0.166 m) had been investigated. The investigation shows the required wax thicknesses necessary to...

In this work, the effect of using inner longitudinal fins in a rectangular encapsulation on the PCM (paraffin wax) melting process was studied numerically and experimentally. An enthalpy transformation method was used in the numerical solution to transfer the equation of energy into a nonlinear equation with a single dependent variable H (enthalpy)...

An experimental investigation to determine the effect of the facing (in-line) and staggered orthogonal rib configuration on heat transfer enhancement in non-rotating and rotating rectangular channel of constant aspect ratio (AR=4) at constant channel orientation β=90º. A Reynolds number range tested in this study was 8000-13500. Rotation effect is...

An experimental investigation to determine the effect of the channel orientation on heat transfer enhancement in stationary and rotating rectangular channel of constant aspect ratio (AR=4) with facing 90º rib turbulators. A Reynolds number range tested in this study was 8000-13500. The effect of channel orientations of β=90 deg and 135 deg with res...

ABSTRACTThe effect of oxygen enrichment on the laminar flames speed for (methanol and ethanol – oxygen –nitrogen) premixed mixtures have been detected practically. Measurement system is designed to measurethe laminar flame speed using a tube – method and optical technique (photodiode). Where the flame frontposition had been located by photodiode. T...

In this paper, the problem of developing turbulent flow in rectangular duct is investigated by obtaining numerical results of the velocity profiles in duct by using large eddy simulation model in two dimensions with different Reynolds numbers, filter equations and mesh sizes. Reynolds numbers range from (11,000) to (110,000) for velocities (1 m/sec...

The present work is an experimental and a numerical investigation of the turbulent fluid flow and heat transfer in an annular channel between two concentric cylinders with heated stationary outer cylinder (constant heat flux) and adiabatic rotating inner cylinder. Numerically, the governing equations are discretized in a finite volume fashion using...

The effect of the type of working fluid, filling ratio and heat input on the performance of a Two Phase Closed Thermosyphon (TPCT) was experimentally investigated in this study. Two thermosyphons were tested; each had the same dimensions, materials and filled with three working fluids (distilled water, R134a and Butanol), different filling ratio (4...

In south Iraq cities